If you can't get Wensleydale, Scoville, then look for something mild and, yes, crumbly. Lancashire cheeses are so widely differing in their tastes - some (Grandma Singleton's Lancashire Tasty, for instance) are incredibly strong (and get stronger by the day!). A white Cheshire might be ok. Not Red Leicester though.

We do seem to have a wonderful selection of cheeses nowadays in the UK - much much better than when I was growing up - and more supermarkets which stock local and regional specialities. Not just cheese, but breads, cakes, biscuits - yum!